50+ Highway Engineer Interview Questions and Answers

The density of soil in the embankment layer varies depending on the type of soil and compaction methods used.

• The density of soil in the embankment layer is typically measured in terms of dry density or wet density.

• Dry density refers to the mass of solid soil particles per unit volume of soil, while wet density includes the mass of water as well.

• The density of soil in the embankment layer is influenced by factors such as moisture content, compaction effort, and soil type.

• For e...read more

Horizontal and vertical alignment is designed based on factors like terrain, speed limit, and safety requirements.

• Terrain analysis is done to determine the best alignment

• Speed limit and design speed are considered for horizontal alignment

• Sight distance and stopping distance are considered for vertical alignment

• Safety requirements like minimum radius of curvature and superelevation are also taken into account

• Computer-aided design software is used for accurate alignment design

Civil engineers face challenges such as managing complex projects, ensuring safety and sustainability, and adapting to technological advancements.

• Managing complex projects with multiple stakeholders and tight deadlines

• Ensuring safety and sustainability in design and construction

• Adapting to technological advancements and incorporating them into engineering practices

• Dealing with budget constraints and optimizing cost-effective solutions

• Addressing environmental concerns and mini...read more

MDD and FDD are measures of soil compaction. Testing involves determining the maximum dry density and optimum moisture content.

• MDD stands for Maximum Dry Density and FDD stands for Field Dry Density

• Testing involves determining the maximum dry density and optimum moisture content of the soil sample

• The testing procedure involves compacting the soil sample in a mold with a known volume and measuring its weight and moisture content

• The test is repeated with varying levels of compa...read more

CBR test is a laboratory test to determine the strength of subgrade soil for highway construction.

• CBR stands for California Bearing Ratio.

• It measures the strength of subgrade soil by comparing the pressure required to penetrate the soil with a standard material.

• CBR values help in designing the thickness of pavement layers for highways.

• Higher CBR values indicate better soil strength and require less pavement thickness.

• For example, a CBR value of 10 means the soil can support 1...read more

Compaction requirements for embankment and subgrade depend on soil type and project specifications.

• Compaction requirements are determined by soil type and project specifications.

• Embankment and subgrade compaction is typically measured by a Proctor test.

• Compaction requirements can range from 90-95% of maximum dry density.

• Compaction must be uniform and consistent throughout the project area.

• Proper compaction ensures stability and longevity of the roadway.

FDD of Subgrade, GSB, WMM in highway engineering

• FDD stands for Flexible Pavement Design

• Subgrade FDD depends on soil type, moisture content, and other factors

• GSB FDD depends on traffic volume, subgrade strength, and other factors

• WMM FDD depends on traffic volume, subgrade strength, and other factors

• FDD helps in determining the thickness of the layers in flexible pavement design

The quantity of material a roller can compact in one day depends on various factors.

• The type and size of the roller will affect its compaction capacity.

• The type and condition of the material being compacted will also impact the quantity that can be compacted.

• The speed and efficiency of the operator operating the roller can influence the daily compaction quantity.

• Environmental factors such as weather conditions and terrain can affect the compaction rate.

• The availability of mat...read more

Yes, I have knowledge of Bbs, bentup, and operating auto level.

• Bbs stands for Bar Bending Schedule, which is a list of reinforcement bars with their lengths and shapes required in a construction project.

• Bentup refers to the process of bending reinforcement bars to the required shape and size before placing them in concrete structures.

• Providing reinforcement in concrete structures enhances their strength and durability.

• Operating an auto level involves setting up the instrument...read more

To maintain a slope in a hill cutting location, proper drainage, erosion control measures, and stabilization techniques must be implemented.

• Ensure proper drainage to prevent water accumulation and erosion

• Implement erosion control measures such as retaining walls, geotextiles, and vegetation

• Stabilize the slope using techniques like terracing, soil nailing, or rock bolting

• Regularly inspect and maintain the slope to address any issues or potential hazards

• Consider the geological ...read more

The grade of GSB used in previous projects varies depending on the specific project requirements.

• The grade of GSB (Granular Sub-Base) used in previous projects is determined based on factors such as traffic load, soil conditions, and project specifications.

• Different grades of GSB, such as GSB-20, GSB-25, GSB-30, etc., may be used in different projects.

• For example, in a high-traffic highway project, a higher grade of GSB like GSB-30 may be used to ensure better stability and d...read more

Superelevation is the banking of a road or highway to counteract the centrifugal force on vehicles during turns.

• Superelevation is the slope or banking provided on the outer edge of a road or highway.

• It helps vehicles to safely negotiate turns at higher speeds by counteracting the centrifugal force.

• The maximum limit of superelevation depends on factors like design speed, curve radius, and type of road.

• For highways, the maximum superelevation limit is typically around 6%.

• Supere...read more

CTSB and GSB are different types of aggregates used in highway engineering.

• CTSB stands for Crushed to Specified Breakdown and GSB stands for Granular Sub Base.

• CTSB is a type of aggregate where the particles are crushed to a specified size and shape, while GSB is a layer of granular material used as a base for pavement construction.

• CTSB is typically used in the construction of flexible pavements, while GSB is used as a sub-base layer to provide a stable foundation for the pave...read more

Engineering work at site involves planning, designing, and overseeing construction projects.

• Surveying and site investigation to gather data

• Designing structures and infrastructure

• Ensuring compliance with regulations and safety standards

• Supervising construction activities

• Quality control and project management

• Example: Designing a highway interchange, overseeing bridge construction

Hard shoulders are provided on highways for emergency stopping, breakdowns, and to improve safety.

• Hard shoulders provide a safe area for vehicles to stop in case of emergencies or breakdowns

• They help reduce the risk of accidents by providing a designated stopping area

• Emergency vehicles can use hard shoulders to reach incidents quickly and safely

• Hard shoulders also allow for easier maintenance and construction work on the highway

The superpave parameter for binders is the Performance Grade (PG) of the binder.

• Superpave is a mix design system for asphalt pavements.

• Performance Grade (PG) is a binder classification system based on temperature susceptibility.

• PG is determined by the high and low temperature properties of the binder.

• For example, PG 64-22 means the binder is suitable for use in areas with maximum pavement temperature of 64°C and minimum pavement temperature of -22°C.

Quantity of PQC can be calculated by multiplying area with thickness

• PQC stands for Pavement Quality Concrete

• Area is calculated by measuring length and width of the pavement

• Thickness is usually 150 mm for highways

• Quantity = Area x Thickness

The density of CTB (Cement Treated Base) varies depending on the mix design and compaction level.

• The density of CTB is typically measured in pounds per cubic foot (lb/ft^3) or kilograms per cubic meter (kg/m^3).

• Higher compaction levels result in higher densities of CTB.

• The density of CTB can range from 120 to 140 lb/ft^3 (1920 to 2240 kg/m^3) depending on the mix design and compaction.

• Density tests are commonly conducted during construction to ensure the CTB meets specificati...read more

Superelevation diagram, junction design, and sight distance are important aspects of highway engineering.

• Superelevation diagram is used to determine the banking of a road to counteract centrifugal force on a curve.

• Junction design involves creating safe and efficient intersections for vehicles, pedestrians, and cyclists.

• Sight distance is the distance a driver can see ahead on the road, and it is crucial for safe driving.

• All three aspects are important for ensuring safe and eff...read more

Bitumen roads are flexible and made of bitumen while RCC roads are rigid and made of reinforced concrete.

• Bitumen roads are cheaper to construct than RCC roads.

• RCC roads have a longer lifespan than bitumen roads.

• Bitumen roads are more suitable for low traffic areas while RCC roads are better for high traffic areas.

• RCC roads require more maintenance than bitumen roads.

• RCC roads are more durable and can withstand heavy loads better than bitumen roads.

Membranes are used in highway engineering for various purposes such as waterproofing, erosion control, and filtration.

• Membranes are used for waterproofing to prevent water from seeping into the pavement layers.

• They are also used for erosion control to protect slopes and embankments from erosion caused by water runoff.

• Membranes can be used for filtration to separate different layers of soil or aggregate materials in road construction.

• Examples of membranes used in highway engin...read more

We use Portland Pozzolana Cement (PPC) in PQC.

• PPC is a type of cement that is commonly used in PQC.

• It is a blend of Portland cement and pozzolanic materials like fly ash, volcanic ash, etc.

• PPC is preferred over Ordinary Portland Cement (OPC) due to its higher durability, strength, and resistance to chemical attacks.

• It also has a lower heat of hydration, which reduces the risk of thermal cracking.

• Examples of PQC projects where PPC was used include the Mumbai-Pune Expressway an...read more

The minimum speed of roller depends on the type of roller and the type of material being compacted.

• The minimum speed of roller is typically specified by the manufacturer.

• The type of material being compacted can also affect the minimum speed of roller.

• For example, a vibratory roller may have a minimum speed of 2 mph for compacting asphalt, while a static roller may have a minimum speed of 1 mph for compacting soil.

Embankment is the raised structure built with earth or other materials, while subgrade is the natural ground level beneath the pavement.

• Embankment is man-made, built with materials like soil, rock, or concrete to raise the road level above the surrounding terrain.

• Subgrade is the natural ground level beneath the pavement, prepared to support the road structure.

• Embankment provides stability and support to the road, while subgrade serves as the foundation for the pavement.

• Exampl...read more

The maximum grade in vertical design refers to the steepest slope that can be used in designing a highway or road.

• The maximum grade in vertical design is typically around 6% for highways and major roads.

• Steep grades can increase the risk of accidents and make it difficult for vehicles to maintain speed.

• Designers must consider factors such as visibility, vehicle performance, and safety when determining the maximum grade.

• For example, a mountainous road may have a maximum grade ...read more

Quantity of DBM can be calculated by using the formula: Volume of DBM = Area x Thickness

• Calculate the area of the road surface to be covered with DBM

• Determine the required thickness of the DBM layer

• Multiply the area by the thickness to get the volume of DBM required

• Consider the wastage factor while calculating the quantity of DBM

• Use appropriate units of measurement for accuracy

The amount of camber provided in BC road varies depending on the road classification and location.

• Camber is the slope provided on the road surface to ensure proper drainage and prevent water accumulation.

• The amount of camber provided is determined by the road classification, traffic volume, and location.

• For example, a rural road may have a camber of 2-3% while an urban road may have a camber of 1-2%.

• The Ministry of Transportation and Infrastructure provides guidelines for cam...read more

The minimum thickness of DBM varies depending on the intended use and traffic volume.

• DBM thickness ranges from 40mm to 100mm depending on traffic volume

• Minimum thickness for low traffic volume is 40mm

• Minimum thickness for high traffic volume is 80mm

• Thickness may also depend on the underlying layers and subgrade

The tolerance of PQC and DLC depends on various factors such as the type of pavement, traffic volume, and climate.

• The tolerance for PQC and DLC varies depending on the type of pavement used.

• Traffic volume and climate also play a significant role in determining the tolerance of PQC and DLC.

• For example, high traffic volume and extreme weather conditions may require a lower tolerance for PQC and DLC.

• The tolerance for PQC and DLC is usually specified in the project specifications...read more

There are two main types of pavement: flexible pavement and rigid pavement.

• Flexible pavement is made up of multiple layers of materials like asphalt and is designed to be flexible to distribute loads over a wider area. Example: asphalt concrete pavement.

• Rigid pavement is made up of a single layer of concrete and is designed to be stiff and strong. Example: jointed plain concrete pavement.

Yes, I know how to mark levels.

• Marking levels involves determining the elevation of a point on the ground and then marking it on a surface or object.

• This can be done using a variety of tools such as a level, a theodolite, or a laser level.

• The marked levels are used to ensure that a surface or object is level or sloped correctly, such as in road construction or building foundations.

P&P stands for Policies and Procedures. Cross section is a view of the road or highway from the side.

• Policies and Procedures (P&P) are the guidelines and rules that govern the design, construction, and maintenance of highways and roads.

• Cross section is a view of the road or highway from the side, showing the different layers of materials used in construction, such as the pavement, subgrade, and drainage.

• Cross section also shows the width and slope of the road, as well as the ...read more

There are several types of rollers used in highway engineering for compaction purposes.

• Vibratory rollers

• Smooth wheeled rollers

• Pneumatic tired rollers

• Sheepsfoot rollers

• Grid rollers

There are two types of grade in GSB - Type A and Type B.

• Type A grade is used for heavy traffic areas and has a higher percentage of larger size aggregates.

• Type B grade is used for low traffic areas and has a lower percentage of larger size aggregates.

• The choice of grade depends on the traffic volume and the type of pavement.

• GSB stands for Granular Sub Base, which is a layer of material placed on the subgrade before the pavement layers are added.

Minimum thickness of PCC for crush barrier is typically 150mm to 200mm.

• Minimum thickness of PCC for crush barrier is usually 150mm to 200mm.

• The thickness may vary depending on the design requirements and load capacity.

• It is important to consult relevant codes and standards for specific guidelines.

• For example, British Standards recommend a minimum thickness of 150mm for PCC crush barriers.

Dense Bituminous Macadam is a type of road construction material made up of well-graded aggregates and bitumen binder.

• Consists of well-graded aggregates like crushed stone, gravel, or sand

• Bound together by bitumen binder

• Provides a strong and durable road surface

• Used in highways, airport runways, and heavy traffic areas

SG top layer finishing work refers to the final layer of asphalt or concrete pavement on a road or highway.

• SG top layer finishing work is the final layer of pavement on a road or highway

• It is typically made of asphalt or concrete

• The purpose of this layer is to provide a smooth and durable driving surface

• It also helps to protect the underlying layers from damage and wear

• Examples of SG top layer finishing work include chip seal, hot mix asphalt, and concrete pavement

Specific gravity of cement is a measure of its density compared to the density of water.

• Specific gravity of cement typically ranges from 3.10 to 3.16.

• It is an important property of cement as it helps in determining the quality and strength of concrete.

• Specific gravity is calculated by dividing the density of cement by the density of water.

• Higher specific gravity indicates higher density and better quality of cement.

Core cutting is a process of extracting cylindrical samples from a structure or material for testing purposes.

• Core cutting is commonly used in construction and civil engineering to assess the quality of materials used in structures.

• The extracted core samples are typically analyzed for strength, density, composition, and other properties.

• Examples of core cutting applications include testing concrete strength in buildings, assessing asphalt quality in roads, and evaluating soil...read more

DBM grade refers to the type of bituminous material used in road construction. Work plan at site includes scheduling of activities and resources.

• DBM grade is determined based on the traffic volume and climate conditions of the area.

• Common DBM grades include DBM 20, DBM 25, and DBM 40.

• Work plan at site involves activities such as excavation, subgrade preparation, laying of base and sub-base layers, and application of DBM.

• Resources needed for road construction include machinery...read more

GSB grade is a type of granular sub-base material used in road construction. It involves various steps like preparation, spreading, compaction, and curing.

• GSB grade stands for Granular Sub-Base grade, which is a layer of material placed on the subgrade of a road.

• The process involves preparing the subgrade, spreading the GSB material evenly, compacting it using rollers, and curing it to achieve the desired strength.

• Proper compaction is crucial to ensure the GSB layer can suppo...read more

Misdesign of bituminous mix can lead to premature pavement distress and reduced pavement life.

• Improper selection of aggregate gradation

• Incorrect binder content

• Inadequate compaction during construction

• Poor quality control measures

• Lack of proper drainage design

• Failure to consider traffic volume and loadings

Types of testing in highway

• Geotechnical testing to assess soil and rock properties

• Pavement testing to evaluate the strength and durability of road surfaces

• Structural testing to ensure the safety and integrity of bridges and other structures

• Traffic flow testing to analyze traffic patterns and optimize road design

• Environmental testing to assess the impact of highways on the surrounding ecosystem

• Safety testing to evaluate the effectiveness of road signs, markings, and barriers

WMM top layer finishing work is the final layer of construction in a road pavement.

• WMM stands for Wet Mix Macadam, which is a type of road construction material.

• The top layer of WMM is usually made up of crushed aggregates and is laid to a thickness of 50-75mm.

• The top layer is compacted using a vibratory roller to achieve the desired density and smoothness.

• The finishing work involves trimming the edges of the road, removing any excess material, and ensuring that the surface i...read more

As a highway engineer, my responsibility in the last site was to oversee the construction of a new highway interchange.

• Managed a team of construction workers and ensured that the project was completed on time and within budget

• Reviewed and approved design plans and made necessary adjustments

• Coordinated with local authorities and stakeholders to ensure compliance with regulations and minimize disruptions to the community

• Conducted regular inspections to ensure quality control an...read more

Admixtures are used to modify the properties of concrete, such as setting time, workability, and strength.

• To improve workability of concrete

• To reduce water content in concrete

• To accelerate or retard setting time of concrete

• To improve strength and durability of concrete

• To reduce corrosion of reinforcement in concrete

• Examples: water reducers, air-entraining agents, accelerators, retarders, superplasticizers

Designing a highway involves careful planning, surveying, and engineering to ensure safety and efficiency.

• Conduct a thorough survey of the area to assess terrain, traffic flow, and environmental impact

• Design the highway layout including lanes, shoulders, medians, and intersections

• Consider factors such as speed limits, sight distances, and road signage

• Incorporate safety features like guardrails, lighting, and proper drainage systems

• Use materials that are durable and suitable f...read more